Phonographic sound box



Mar. 13, 1923. 1,448,090

W. SCOTT -HONOGRAPHIC SOUND BOX Filed July 50, 1921 -l N VEN TOR.

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Patented .Mar. 13, 1923.

WALTER S COTT, OF SHERIDAN, WYOMING.

PHONOGRAPHIC SOUND BOX.

Application filed July 30, 1921. Serial No: 488,566.

. the accompanying drawings.

This invention relates to sound boxes for phonographs, telephones, andlike instruments, and particularly to means for reinforcing andmodifying the sound transmitted from the sound box to the amplifier.

The general object of the invention is to provide a sound box whetherfor phonographs or telephones having adjacent the diaphragm a pluralityof stretched coiled springs extending transversely across the spacebehind the diaphragm, the sound waves acting to vibrate these springsand a being reinforced by, the vibrations of the springs.

A further object is to provide a sound modifier of this character whichmay be in.- serted in sound boxes.

And still another object is to so construct the sound box as to securefull vibration for the springs.

My invention is illustrated in the accompanying drawings, wherein Figure1 is a front elevation of a sound box constructed in accordance with myinvention;

Figure 2 is a like view to Figure 1, but with the diaphragms broken awayand the bar 19 broken away;

Figure 3 is a section on the line 33 of Figure 1;

Figure 4 is a plan view of thespring supporting ring;

Figure 5 is a fragmentary sectional view of the spring supporting ring;

Figures 6 and 7 are face views of the two diaphragms. 1

Referring to these drawings, 10 designates the body of'the sound boxwhich is formed to provide the usual sound chamber 11 and to provideaseat 12 for a gasket 13. Resting upon this gasket is a transverselyextending diaphragm 14. whichextends diametrically across the soundchamber 11 andwhich has a uniform width except at the ends where it isrounded to fit the gasket,

this diaphra m thus leaving open. spaces on by a suitable gasket 15 is asecond. diaphragm 16 which is circular in form so as to fit snuglywithin the circumferential wall of the sound box, this second diaphragmbeing spaced from the diaphragm 14 by the gasket 15 and being held inplace by a gasket 17. Preferably this gasket 17 is engaged by anexternally screw-threaded clamping ring 18 so that pressure may beapplied to the gas kets and to the two diaphragms to hold the same inplace.

The stylus bar is pivotally mounted upon the side wall'of the sound box,and to this end I provide a transversely extending supporting member 19formed with an outwardly projecting lug 2O perforated for engagementwith a stylus 21, this being held in place by a set screw. Attached tothis member 19 is the arm 22 which is engaged with the diaphragm 16. Themember 19 is held to the wall of the sound box. by two screws 22 whichextend through relatively large apertures 23 in the member 19 so thatthe stylus barhas a rocking movement on these screws. Small rubbergaskets 23 are jacent wall of the sound box so that the member 19 hasthe least possible rocking engagement with the wall of the sound box.

The. inner end of the sound box is provided with the neck 25 having agasket seat 26 defining a' central throat or opening 27.

Resting against this seat is a gasket 28, and i v disposed on thisgasket is the outwardly flanged end of a slit tube 29. Resting againstthis flanged end is the gasket 30, this gasket being held in place bythe annulus 31, through which screws 32, pass. The slit tube 29 isslitted at its outer end. The neck 25 is also slotted and a pin projectsradially from the slit tube-into this slot or notch.

The means for modifying the sound and reinforcing the sound vibrationscomprises a metallic ring 33, preferably of resilient material. whoseends are hook-shaped so that the ends of the ring may be engaged witheach other, this ring being formed with a plurality of small, struck-uptongues 34'withwhich a plurality of transversely extending coiledcontractile springs 35 are engaged.

These springs extend transversely across the sound box-preferablyparallel to the arm 21 and at right. angles to the longer axis of thediaphragm 14;. The ring 33 is disposed on a seat 36 formed between thethroat 27 of the sound box and the Seat 12. These springs in actualpractice will have coils of approximately -3," in diameter more or lessand will be very closely coiled. An ordinary sized sound box will haveeight springs, the springs being set relatively close to each other sothat the springs cannot fail to be vibrated by the pulsations of the airwithin the sound box and in the sound chamber.

I am aware of the fact that it has been proposed to reinforce soundvibrations in the sound boxes of telephones by the use of radiallydisposed coiled springs, which springs are supported, however, only attheir inner ends and are not stretched strings, but I have found inactual practice that in order that these springs shall be stiff enoughto stand radially outward that they will not be caused to vibrate bysound vi-v brations. Obviously, if any of these springs should at'theirends touch the diaphragm or touch the metal of the sound box, they wouldcause a rattling noise which would be unpleasant. Inasmuch as thesprings in my device are supported at opposite ends and the springs arerelatively taut or under tension, it follows that there can be nocontact between the springs on either the diaphragm or the metal of thesound-box. I am also aware of the fact that it is common to providestretched strings extending along the amplifiers of phonographs, thesestrings, however, not being coiled springs. Inasmuch as they are notstretched across the path of movement of the sound waves, they are notstrongly affected by the sound waves or vibrations.

Particular attention is called to the fact that there are two diaphragmsin my construction and that the inside one has its lateral edges cutaway so that the diaphragm acts to .cause thesound waves to strikeagainst the ends of the springs and cause the full vibration of thesprings.

I do not wish to be limited to the use of this device with phonographsound boxes,

as it may be also used in telephone soundboxes, megaphones, and thelike.

I claim 1. In a sound transmitting instrument having a sound chamber, aseries of coiled a series of coiled contractile springs extendingparallel to each other and under tension, said springs of differentlengths and extending diametrically across the sound chamber adjacentthe diaphragm.

3. In a sound transmitting instrument having a sound chamber and adiaphragm and behind the same, a ring disposed within the sound chamberin spaced relation to the diaphragm, and a series of coiled contractilesprings attached at their ends to said ring and extending diametricallyacross the ring and in the path of movement of the sound waves and undertension.

4:. As an article of manufacture, a sound modifier for soundtransmitting instruments comprising a resiliently expansible ring, thering being split, and a series of coiled contractile springs disposedclosely adjacent each other and extending transversely across the spacedefined by the ring and connected at their extremities to the ring, thesprings being under tension.

5. A phonographic sound box having a sound chamber, a diaphragmextending across the sound chamber, coiled springs extending, parallelto each other and under tension and disposed immediately behind thediaphragm and extending across the path of the sound waves, the rearwall of the diaphragm having an opening Whose axis is at right angles tothe plane in which the springs are disposed.

6. As an article of manufacture, a sound modifier for sound transmittinginstruments comprising a resiliently expansible ring having inwardlyprojecting, oppositely disposed tongues extending inward from the ring,and a series of coiled, contractile, stretched strings under slighttension having their ends engaged with said tongues and supportedthereby, the springs extending parallel to each other and transverselyacross the ring. a

In testimony whereof I hereunto aflix my signature. WALTER SCOTT.

